(1) Field of the Invention
The present invention relates to heading sensors for underwater towed arrays, and in particular to a high performance solid state heading sensor operated in conjunction with a data processing orientation formulation for towed acoustic arrays.
(2) Description of the Prior Art
Current towed acoustic sonar arrays use magnetic heading sensors to measure the shape of the array to determine the azimuthal bearing of acoustic sources of interest and to allow for the determination of array shape for improved beamforming performance. The towed array application requires very high accuracy measurement of the horizontal angle between the axis of the array and the magnetic field vector, even at high earth latitudes where the horizontal component of the magnetic field vector may only be 10% of the total vector magnitude. Existing heading sensors use fluxgate floating ring-core gimbal magnetometers that suffer significantly from reliability and production problems. Due to the gimbal design of these sensors, the heading sensor output becomes very noisy and completely unreliable due to the flow induced vibration that excites the gimbal close to its resonance during vessel maneuvers and during erratic array motion.
For this reason, what is needed is a heading sensor that provides accurate heading measurements when the array is under dynamic motion within the constraints of power consumption, processing and space that are imposed by implementation into an underwater towed acoustic array.